Drawasaurus - Drawasaurus is an online drawing & guessing game you can play with friends or strangers.
Inkscape - Inkscape is a free, open source professional vector graphics editor for Windows, Mac OS X and Linux.
LetsDraw.It - Guess and Draw, Drawing Battle, Pictionary, Copy picture - online drawing games where you can compare your skill with others.
Sketch - Professional digital design for Mac.
skribbl - Word guessing based on drawing.
Affinity Designer - Professional creative software, exclusively for Mac.